The present invention relates to tipping systems. Particularly but not exclusively, it relates to a tipping system incorporated in a vehicle and wherein side tipping is involved such as in a doorless side tipper vehicle. Doorless side tipping has been proposed to be provided in road and rail trucks, trailers and semi-trailers for bulk or mass material haulage and transport.
In International patent application WO89/02838 a side tipper support system for a side tipping bulk transport vehicle has been disclosed. The container body has a hinge at one side providing a low pivot point and hydraulic rams positioning on the other side. The rams are two stage, the first stage being single acting and the second stage being double acting with a balancing over ccentre valve. The body in the transport or non-tipped position is supported on feet so that the hinge and rams do not support the load. Further, the body is inwardly inclined on the tipping side to reduce the extent of tipping movement required to discharge the contents of the body.
The problems with the currently known constructions of side tipping bodies are that if the body is of the conventional generally rectangular cross-section, it is either necessary to provide doors on the dicharge side of the body, which are opened when the body is tipped, or it is necessary for that side of the body to be inclined inwardly and downwardly from the top edge when the body is in the normal position in order to discharge all of the contents of the body when tipped. The provision of doors on the side of the body presents a number of difficulties, such as maintaining the required strength in the doors and the body, and the difficulties that may be experienced in opening and closing the doors, particularly after a significant period of use when the doors and/or adjacent portion of the body may become distorted and accordingly present major difficulties in fitting and closing same.
In an attempt to avoid the problems associated with doors on the side of a tipping body, it has been proposed to incline the side wall of the body on the side to which it is tipped. This inclining of the side wall enables the body to be tilted to a less degree and still obtain discharge of the materials down the inclined wall when the body is in its maximum tipped position. This construction, however, has disadvantages in that the inclining of the side reduces the total carrying capacity of the body. Also it is necessary to effect a substantial extent of pivotal movement of the body so that the inclined side is sufficiently downwardly inclined during tipped for all of the contents to be discharged. This degree of pivotal movement can lead to instability in the vehicle during tipping due to the substantial degree of displacement of the centre of gravity of the body towards the tipping side.